Environmental Benefits Of Smart Growth

Many studies show the environmental benefits of smart growth. Development guided by smart growth principles can minimize air and water pollution, encourage brownfields clean-up and reuse, and preserve natural lands.

The built environment — the places where we live, work, shop, and play — has both direct and indirect effects on the natural environment. Where and how we develop directly affects natural areas and wildlife habitat and replaces natural cover with impervious surfaces such as concrete or asphalt. Development patterns and practices also indirectly affect environmental quality since they influence how people get around. Separating land uses, spreading development out, and providing little or no public transportation or safe walking and biking routes foster greater reliance on motor vehicles. As development grows more dispersed, people must drive further to reach their destinations, leading to more and longer vehicle trips. These increased trips create more air emissions and greenhouse gases that contribute to global climate change. Ultimately, air pollution and climate change can also harm water quality and wildlife habitat.

Smart growth practices can lessen the environmental impacts of development with techniques that include compact development, reduced impervious surfaces and improved water detention, safeguarding of environmentally sensitive areas, mixing of land uses (e.g., homes, offices, and shops), transit accessibility, and better pedestrian and bicycle amenities.

In practice, these techniques have created tangible environmental improvements. A 2000 study found that compact development in New Jersey would produce 40 percent less water pollution than more dispersed development patterns.1 A 2005 Seattle study found that residents of neighborhoods where land uses were mixed and streets are better connected, making non-auto travel easier and more convenient, traveled 26 percent fewer vehicle miles than residents of neighborhoods that were more dispersed and less connected.2 While individual smart growth methods can yield significant environmental improvements, a synergistic approach combining policies and programs can deliver even greater environmental benefits.

Air Quality — According to a 1999 EPA evaluation of the environmental benefits of infill versus greenfield development (PDF)(35 pp, 368K, About PDF), siting a new development in an existing neighborhood, instead of on open space at the suburban fringe, can reduce miles driven by as much as 58 percent. Communities that make it easy for people to choose to walk, bicycle, or take public transit can also reduce air pollution by reducing automobile mileage and smog-forming emissions.

Water Quality — Compact development and open space preservation can help protect water quality by reducing the amount of paved surfaces and by allowing natural lands to filter rainwater and runoff before it reaches drinking-water supplies. Runoff from developed areas often contains toxic chemicals, phosphorus, and nitrogen; nationwide, it is the second most common source of water pollution for estuaries, the third most common for lakes, and the fourth most common for rivers. 3

Brownfields Redevelopment — Brownfields are abandoned, idled, or underused industrial and commercial facilities where redevelopment is complicated by real or perceived environmental contamination. Cleaning up and redeveloping a brownfield can remove blight and environmental contamination, catalyze neighborhood revitalization, lessen development pressure at the urban edge, and use existing infrastructure.

Open Space Preservation — Preserving natural lands and encouraging growth in existing communities protects farmland, wildlife habitat, outdoor recreation, and natural water filtration that ensures clean drinking water. The 2000 Rutgers University Center for Urban Policy and Research study for the state of New Jersey found that, compared to less compact growth patterns, planned growth could reduce the conversion of farmland by 28 percent, open space by 43 percent, and environmentally fragile lands by 80 percent.